Engine control apparatus



Nov. 24, 1942. J. a. DYER ENGINE CONTROL APPARATUS Filed Nov. 19, 1932 5 Sheets-Sheet 1 wau sucT/on/ Nov. 24, 1942. J. B. DYER ENGINE CONTROL APPARATUS 5 Sheets-Shet 2 Filed Nov. 19, 1932 To ansoLl/v an 066-- M m w m e U n 5 a a, /0\I. 9 a ffi M I J a d m ml Patented Nov. 24, 1942 UNITED STATES PATENT OFFICE ENGINE CONTROL APPARATUS John B. Dyer, Pendleton, Ind., assignor, by mesne assignments, to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application November 19, 1932, Serial N 0. 643,379

18 Claims.

to the operation of one or more of the control devices which must be actuated by the operator of the engine or vehicle to control the operation thereof under ordinary operating conditions.

It is a further object of this invention to provide means operated by the engine itself for causing the starting motor to become inoperative and to effect the disengagement of the motor driven pinion from the flywheel gear and to prevent the starting motor from becoming operative or the pinion from being moved into engagement with the engine gear as long as the engine is operating under its own power.

According to this invention, these objects are accomplished by the provision of an electromagnet which is operative to shift the motor-driven pinion into mesh with the engine flywheel gear and to control the disengagement of the pinion therefrom when the magnet is de-energized. The winding of said magnet is in circuit with a magnetic switch which closes the circuit of the starting motor so that the closing of said switch closes the circuit of the starting motor and causes energization of said magnet. The switch referred to is a magnetic switch which is energized when the ignition switch and a switch operated by the accelerator pedal which controls the flow of combusti'ble mixture to the engine, are both closed. The de-energization of both the electromagnet which shifts the motor driven pinion and the magnetic switch is effected in either one of three ways, first. by engine suction, second, by the action of the generator when operated at more than a predetermined speed, and third, by the action of both engine suction and the generator.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accoms pany drawings wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a wiring diagram of one form of this invention in which the starting motor is rendered inoperative by action of engine suction.

Fig. 2 is a similar diagram of a modified form of the invention in which the starting motor is rendered inoperative by the generator.

Fig. 3 is a similar diagram of a further modification in which the action of engine suction and the generator are both. effective to render the starting motor inoperative.

Referring to Fig. l in the drawings, the starting motor is indicated at 20 having a ground connection 2|, and has an armature shaft 22 on which is splined a sleeve 24, which is secured to one member of an overrunning clutch 26, the

other member of which is secured to or integral with the driving pinion 28, adapted to be moved into engagement with the gear formed on the engine flywheel in order to turn said gear and start the engine whenever the starting motor is operative. The sleeve 24 is moved to the right in Fig. l in order to effect engagement of the pinion 28 with the flywheel gear 30 and simultaneously to close the circuit between the motor 20 and the battery is closed in order to cause the starting motor to become operative.

To this end the sleeve 24 is provided with a grooved collar 32 which is slidable on the shaft 22 and said collar is engaged by a pin 34 which projects from the lower end of the lever 36 suitably pivoted at 38 and pivotally connected at the upper end with the armature 40, indicated in its entirety by the reference connection 42. The lower part of the lever 38 may be bifurcated to form a yoke and there may be a plurality of pins engaging the collar 32 instead of the single pin 34 if desired. When the solenoid is energized, the lever 36 is rocked in a counter-clockwise direction and through the medium of collar 32, compresses a. spring 44 which surrounds the sleeve 24 between the collar and the clutch 26 to move the pinion into engagement with the flywheel gear in the usual manner. The solenoid has a winding 46 which is grounded through the connection 48 and connected at its opposite end by a wire 50 which is connected by wire 5| with the starting motor and is connected directly to one of the fixed contacts 52 of a magnetic switch indicated in its entirety. by the letter A. The other fixed contact 54 of this magnetic switch is connected by a wire 56 with a wire 58, which extends from a generator 60 grounded through the connection 62 to a storage battery 64, which is grounded by any suitable connection 66. The switch A is provided with a movable contact 68 which is secured to or integral with a rod 10 forming the armature of said switch A and movable within a core I2. A spring I3 serves to normally hold the movable contact 68 out of engagement with the fixed contacts 52 and 54 when the magnetic switch A is not energized, as when the engine is not running. The switch A has also a winding I4 which is received within a housing I6 and this winding is connected at one end with a wire 78 through which it is grounded. The winding is connected at its other end with a wire 80 which extends to one fixed terminal 82 of a suction operated switch indicated in its entirety by the letter B and provided with a second fixed terminal 84. The switch B includes also a movable contact member 86 operable in a manner hereinafter more fully described, which is adapted to engage both of the fixed contacts 82 and 84 when the engine is not running. The fixed contact 84 is connected by a wire 88 with the movable contact of 'a switch adapted to be operated by the accelerator pedal which controls the quantity of mixture supplied to the engine and indicated in its entirety by the letter C. This switch is provided with a fixed contact 92 which is connected by a wire 94 to a wire 96 leading from the fixed contact 98 of the ignition switch to the ignition system of the engine. The movable contact I00 of the ignition switch is connected by a wire I02 with the wire 58 which leads from the generator to the battery.

The switch B is in closed position when the engine is stationary and in order to start the engine the operator first closes the ignition switch and then closes the switch C in a manner which will be apparent from the description thereof appearing hereinafter. When these two switches are closed, current will flow from the battery to ground through the connection 66 and from the battery through wires 58, I02, the ignition switch, wires 96 and 94, contacts 92 and 90, wire 88, switch B and wire 80 to the winding of the magnetic switch A and thence through wire I8 to ground again. This will cause energization of the magnetic switch A which will cause the movable contact 68 to engage the contacts 52 and 54 so that when the switch A is closed, current will flow from the battery to ground through the connection 66 and from the battery through wires 58 and 56, the switch A and wire 50 to the winding of the solenoid 42 which will be energized to shift the driving pinion into engagement with the gear 30 while at the same time current will pass from the wire 50 through the wire to the starting motor and through the ground connection 2I to ground again. From the above, it will be clear that when the ignition switch and the switch C are closed, the switch B being already closed, the magnetic switch A will be energized so that it closes to simultaneously complete the circuit between the starting motor 20 and the battery 64 and to energize the solenoid 42 which shifts the motor-driven pinion 28 into engagement with the flywheel gear 30. The suction-operated switch B comprises two sheet metal shells I04 and I06 which are joined together in any suitable way to form a fluid-tight chamber and between flanges projecting from said shells is a flexible diaphragm I08. On one side of the diaphragm is a sheet metal disk IIO and on the other side, two sheet metal disks H2 and H4 respectively, while extending through the diaphragm and the three disks is the reduced end II6 of a short rod II8, which is integral with the movable contact 86 and is provided with a shoulder upon which the disk I I0 rests, the other end of the rod being riveted over the disk I I4 to hold the entire assembly together, while the disks operate to reinforce the diaphragm. The contacts 84 and 82 are supported by the shell I06 but are suitably insulated therefrom. A nipple I20 having a flange I22 projecting therefrom, extends through an opening in the shell I04 and a Washer I24 externally threaded on the nipple, clamps the shell between itself and the flange to form a fluid-tight joint. A coupling member I26 is threaded on the nipple and connects the nipple with a tube I28 of suitable flexing material such as copper, which extends to and is suitably connected to the intake manifold. A spri ng I30 is received within the nipple and engages the disk II4 to hold the diaphragm in the position normally shown in the drawings with the movable contact 86 in engagement with the two fixed contacts 82 and 84.

Obviously, when the engine begins to run under its own power, the suction communicated from the intake manifold through the tube I28 moves the diaphragm I08 to a position to disengage the movable contact from the two fixed contacts of the switch A and thus breaks the circuit through the winding of the magnetic switch A which thereupon becomes de-energized and upon opening, breaks the circuit not only through the solenoid 42 to cause disengagement of the driving pinion 28 from the gear 30, but at the same time breaks the circuit of the starting motor and causes same to come to a stop.

The construction of the switch C is fully disclosed and claimed in applicants copending application Serial No. 594,553 and the details of its construction need not be disclosed herein. For purposes of this disclosure, it is sufiicient to say that said switch comprising a housing I32 which is secured in any desirable manner to a rod I34 adapted to be connected with the mechanism which operates the throttle of the carburetor to control the supply of fuel mixture to the engine. A spring I36 is received between the housing and some stationary portion of the vehicle or engine to normally hold the rod I34 in its inoperative position. The contact 92 is fixed in the housing I32 and the contact 90 is so mounted as to be slidable in said housing. The contact 90 is moved by depression of a rod I38 provided with an operating button or pedal I40 and slidably mounted in the housing I32. A spring I42 of lesser strength than the spring I36 is received around a rod I38 and normally holds the rod in the position shown in the drawings. When the button or pedal I40 is pushed downwardly, the spring I42 is first collapsed as the contact is moved into engagement with contact 92 and after this takes place, the entire assembly is moved downwardly as the accelerator rod is operated to open the throttle. The contacts and 92 remain in engagement throughout substantially the entire operation of the vehicle and consequently the switch B operable by engine sucion, is relied upon to break the circuit through the switch A and by means of the switch A, to break the circuit through the starting motor and the solenoid 42 in order to prevent any possible operation of the solenoid, or any possible closing of the starting motor switch during the operation of the engine. Therefore, although the ignition switch remains closed and the switch 0 remains closed, the switch B is effective to prevent the engagement of the pinion 28 with gear 30, or the closing of the starting motor circuit as long as the engine continues to run under its own power. It will be understood, however, that the suction which is communicated to the diaphragm I08 during the cranking of the engine by the starting motor is insufficient to open the switch B and does not become sufiicient to do so until the engine is running under its own power.

The modified form of the invention disclosed in Fig. 2 is somewhat like that disclosed in Fig. 1 and previously described, but in this modified form of the invention the suction-operated switch B has been entirely omitted and the circuit through the winding of the magnetic switch is closed by actuation of the ignition switch and the switch C, as in the previously described embodiment of the invention, but the magnetic switch A is caused to open by action of the generator which sets up a countervoltage therein.

The construction of the starting motor, the solenoid for shifting the motor-driven pinion and the switch A, with the exception of the circuit for said last named switch, is all exactly the same as in the first described form of the invention and, therefore, will not be described herein, but the similar parts are indicated by the same reference characters with the suflix a added thereto.

It will be noted that in this embodiment of the invention the Winding Ila of the magnetic switch is connected at one end by a wire I50 with the wire 58a which leads from the battery to the generator at a point between the generator and the usual cut-out relay so that the switch A instead of having a separate ground connection as in the device shown in Fig. 1, is grounded through the ground connection 62a of the generator. At the other end, the Winding 14a is connected by a wire I52 directly with the fixed contact 92a of the switch C instead of being connected to a suction operated switch, as in the previously described form of the invention. The movable contact 90a of the switch C is connected by a wire I54 with the wire I56 which leads from one fixed contact I58 of the ignition switch to the gasoline gauge of the engine. Another contact 98a of the ignition switch is connected by wire 95a to the ignition system of the engine, while the movable contact of the ignition switch comprises two contact arms Ia and I59 adapted to engage contacts 90a and I58 respectively. Other than these changes in the circuit and the omission of switch B, this device is exactly the same as in the first described form and the detailed construction of switches A and C is also identical with the corresponding switches in Fig. 1.

The operation of this form of the invention is substantially as follows. If, when the engine is not running, the ignition switch and the switch C be closed, current will flow from the battery to energization of the magnetic switch which is then opened by the spring 13a resulting in the de-energization of the solenoid to cause the disengagement of the pinion 28a. from the gear 30a and the simultaneous breaking of the circuit through the starting motor which causes it to stop. As long as the generator operates at sufficiently high sp ed, the switch A remains open and the generator is so designed that it sets up sufficient counter-voltage for this purpose at any possible speed of operation of the engine under its own power. It will be understood that the generator may or may not be of the separately excited type. It is not so illustrated herein, but the separately excited type of generator is somewhat more sensitive setting up a higher countervoltage at a lower operating speed and, therefore, would probably be preferable to use.

In the form of the invention disclosed in Fig. 3, the structure is a combination largely of the device disclosed in Figs. 1 and 2. In this form of the invention all three of the switches A, B and C are employed to control the circuits of the starting motor and the solenoid for shifting the motordriven pinion, but in this device the circuit through the magnetic switch A is controlled not only by the suction operated switch B, as in Fig. 1, but is controlled in addition thereto by the action of the generator which sets up a countervoltage in the winding of the switch A in the same way as in the form of the invention disclosed in Fig. 2. The only difference between the construction disclosed in Fig. 3 and in Fig. 1 lies in the connection of the winding of the magnetic switch with the wire leading from the battery to the generator so that said magnetic switch is grounded through the generator and by means of this connection, the generator is eifective to set up a counter-voltage in said magnetic switch as described in connection with Fig. 2. Since with this single exception the construction shown in Figs. 1 and 3 are identical, the description thereof will not be repeated, corresponding parts in Fig. 3 being indicated by the same reference characters as in Fig. 1 with the suifix b added thereto.

As above stated, the winding 14b of the magnetic switch A is in this form of the invention,

connected by a wire I60 to the wire 58b between same way as set forth in the description of Fig. 1.

Therefore, in this form of the invention the applicant has provided two means for controlling the circuit through the magnetic switch A which controls the circuit of the starting motor and ground through connection 660. and from the battery through wires 58a, I02a, the ignition switch, wire I54, the switch C, wire I52, the winding I ia, wires I50 and 58a to the generator and through the connection 62a to the ground. When this takes place, the switch A is closed and current will flow, as previously described, from the battery through the main switch A through the solenoid 42a to ground and through the starting motor 20a to ground, resulting in the shifting of the pinion 28a into engagement with the gear 30a by the solenoid and the immediate operation of the starting motor. When the engine is started by the action of said starting motor, the generator is operated and when operating at a predetermined speed, a counter-voltage is set up in the winding 14a by reason of the connection I50 so that this counter-voltage causes the dethe shifting of the driving pinion, one of these means being the suction-operated switch B and the other, the action of the generator. The means are independent and if the generator should for any reason fail to develop suificient current to set up the counter-voltage necessary to cause the de-energization of the magnet of the switch A, the enginesuction would operate the switch B to cause the motor to become inoperative and to prevent it becoming operative while the engine is running. Similarly, if the suction under certain conditions of operation were to become so low as to fail to open the switch B, the generator is designed to cause the de-energization of the switch A and prevent the operation of the starting motor irrespective of the failure of engine suction to open the switch B.

While the forms of embodiment of the present invention as herein disclosed, constitute preferred forms, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electrically operated means for establishing driving connection between the starting motor and the engine and also in circuit with said current source, a single control switch for closing the circuit between the current source and the starting motor and also between the current source and said electrically operated means, means for variably controlling the quantity of combustible mixture supplied to the engine while the starting motor is being operated to start the engine and means operated by the mixture controlling means for controlling the action of said control switch. a

2. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electrically operatedmeans for establishing driving connection between the starting motor and the engine and also in circuit with said current source, a single control switch for simultaneously closing the circuit between the current source and the starting motor and also between the current source and said electrically operated means, means for variably controlling the quantity or" combustible mixture supplied to the engine while the starting motor is being operated to start the engine and means operated by the mixture controlling means for controlling the action of said control switch.

3. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electrically operated means for establishing driving connection between the starting motor and the engine and also in circuit with said current source, a single control switch for closing the circuit between the current source and the starting motor and also between the current source and said electrically operated means, means for variably controlling the quantity of combustible mixture supplied to the engine while the starting motor is being operated to start the engine, means operated by the mixture controlling means for causing the closing of said control switch and means operable by the engine when it becomes self-operative to effect opening of the control switch.

4. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electrically operated means for establishing driving connection between the starting motor and the engine and also in circuit with said current source, a single control switch for closing the circuit between the current source and the starting motor and also between the current source and said electrically operated means, means for variably controlling the quantity of combustible mixture supplied to the engine while the starting motor is being operated to start the engine, means operated by the mixture controlling means for causing the closing of said control switch and means operable by engine suction when the engine becomes self operative to eiiect opening of the control switch.

5. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electrically operated means for establishing driving connection between the starting motor and the engine and also in circuit with said current source, a single control switch for closing the circuit between the current source and the starting motor and also between the current source and said electrically operated means, means for variably controlling the quantity of combustible mixture supplied to the engine while the starting motor is being operated to start the engine, means operated by the mixture controlling means for causing the closing of'said control switch, a generator, and means operable by the generator when the engine becomes self operative to effect opening of the control switch.

6. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electrically operated means for establishing driving connection between the starting motor and the engine and also in circuit with said current source, a single control switch for closing the circuit between the current source and the starting motor and also between the current source and said electrically operated means, means for variably controlling the quantity of combustible mixture supplied to the engine while the starting motor is being operated to start the engine, means operated by the mixture controlling means for causing the closing of said control switch, a generator, and means operable by engine suction and the generator when the engine becomes self operative to effect opening of the control switch.

'7. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electrically operated means for establishing driving connection between the starting motor and the engine and also in circuit with said current source, a single control switch for closing the circuit between the current source and the starting motor and also between the current source and said electrically operated means, means for variably controlling the quantity of combustible mixture supplied to the engine while the starting motor is being operated to start the engine, means operable by the mixture controlling means for causing the closing of said control switch and efiective throughout the major portion of the movement of said mixture controlling means as the latter is moved to regulate the mixture supply, and means responsive to self operation of the engine for effecting the opening of the control switch irrespective of the position of the mixture controlling means.

8. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electrically operated means for establishing driving connection between the starting motor and the engine and also in circuit with said current source, a single control switch for closing the circuit between the current source and the starting motor and also between the current source and said electrically operated means, means for variably controlling the quantity of combustible mixture supplied to the engine while the starting motor is being operated to start the engine, a second control switch operable when closed to cause the main control switch to be closed, means whereby the second in circuit therewith, an electrically operated means for establishing driving connection between the starting motor and the engine and also in circuit with said current source, a single control switch for closing the circuit between the current source and the starting motor and also between the current source and said electrically operated means, means for variably controlling the quantity of combustible mixture supplied to the engine while the starting motor is being operated to start the engine, a second control switch operable when closed to cause the main control switch to be closed, means whereby the second control switch is held closed by the mixture controlling means throughout the greater part of the movement of said mixture control means to regulate the mixture supply, and means operable by the suction of the engine when it becomes self operative to cause the main control switch to be opened irrespective of the condition of the second control switch.

10. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electrically operated means for establishing driving connection between the starting motor and the engine and also in circuit with said current source, a single control switch for closing the circuit between the current source and the starting motor and also between the current source and said electrically operated means, means for variably controlling the quantity of combustible mixture supplied to the engine while the starting motor is being operated to start the engine, a second control switch operable when closed to cause the main control switch to be closed, means whereby the second control switch is held closed by the mixture controlling means throughout the greater part of the movement of said mixture control means to regulate the mixture supply, a generator, and means whereby the generator causes the opening of the main control switch when the engine becomes self operative irrespective of the condition of the second control switch.

11. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electrically operated means for establishing driving connection between the starting motor and the engine and also in circuit with said current source, a single control switch for closing the circuit between the current source and the starting motor and also between the current source and said electrically operated means, means for variably controlling the quantity of combustible mixture supplied to the engine while the starting motor is being operated to start the engine, a second control switch operable when closed to cause the main control switch to be closed, means whereby the second control switch is held closed by the mixture controlling means throughout the greater part of the movement of said mixture control means to regulate the mixture supply, a generator and means operable by engine suction and the generator to cause the opening of the main control switch when the engine becomes self operative irrespective of the condition of the second control switch,

12; Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electrically operated means for establishing driving connection between the starting motor and the engine and also in circuit with said current source, a single control switch for closing the circuit between the current source andthe starting motor and also between the current source and said electrically operated means, means for variably controlling the quantity of combustible mixture supplied to the engine while the startingmotor is being operated to start the engine, a second control switch operable when closed to cause the main control switch to be closed, means whereby the second control switch is held closed by the mixture controlling means throughout the greater part of the movement of said mixture control means to regulate the mixture supply, means operable by engine suction to cause the opening of the main control switch when the engine becomes self operative, irrespective of the condition of the second control switch, a generator, and means whereby the generator prevents .closing of the main control switch as long as the engine runs under its own power regardless of engine suction.

13. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electromagnet for establishing driving connection between said starting motor and the engine and provided with a winding in circuit with the current source, a single magnetic switch for controlling the circuits between the current source and starting motor and between the current source and said magnet, a second switch in circuit with said magnetic switch and effective when closed to cause the closing of said magnetic switch, means for variably controlling the quantity of mixture supplied to the engine when the starting motor is being operated .to start the engine, and operable to close said second switch as the mixture controllingmeans is moved to variably control the mixture supply, and means operable when the engine becomes self operative to cause the opening of said magnetic switch.

14. Starting apparatus forinternal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electromagnet for establishing driving connection between said starting motor and the engine and provided with a winding in circuit with the current source, a single magnetic switch for controlling the circuits between the current source and starting motor and between the current source and said magnet, a second switch in circuit with said magnetic switch and eirective when closed to cause the closing of said magnetic switch, means for variably controlling the quantity of mixture supplied to the engine when the starting motor is being operated to start the engine, and operable to hold said second switch closed as the mixture controlling means is moved to different positions to regulate the mixture supply to the engine, and means operable by engine suction to cause said magnetic switch to be opened when the engine is operating under its own power irrespective of the condition of the switch operated by the mixture controlling means.

15. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electromagnet for establishing driving connection between said starting motor and the engine and provided with a winding in circuit with the current source, a single magnetic switch for controlling the circuits between the current source and starting motor and between the current source and said magnet, a second control switch in the circuit between the magnetic switch and said current source and effective when closed to cause the closing of said magnetic switch, means for variably controlling the quantity of mixture supplied to the engine and operable to hold said second switch closed asthe mixture controlling means is moved to diiferent positions to regulate the mixture supply to the engine, a third control switch in the circuit between the magnetic switch and said current source, and means operable by engine suction for opening said third control switch when the engine is operating under its own power to eilect opening of the magnetic switch to be opened and cause the starting motor to be rendered inoper in circuit therewith, an electromagnet for establishing driving connection between said starting motor and the engine and provided with a winding in circuit with the current source, a single magnetic switch for controlling the circuits between the current source and starting motor and between the current source and said magnet, a second switch in circuit with said magnetic switch and effective when closed to cause the closing of said magnetic switch, means for variably controlling the quantity of mixture supplied to the engine when the starting motor is being operated to start the engine, and operable to hold said second switch closed as the mixture controlling means is moved to different positions to regulate the mixture supply to the engine, a

switch operated by the mixture controlling means.

17. Starting apparatus for internal combustion 1 engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electromagnet for establishing driving connection between said starting motor and the engine and provided with a winding in circuit with the current source, a single magnetic switch for controlling the circuits between the current source and starting motor and between the current source and said magnet, a second control switch in the circuit between the magnetic switch and said current source and effective when closed to cause the closing of said magnetic switch, means for variably controlling the quantity of mixture supplied to the engine and operable to hold said second switch closed as the mixture controlling means is moved to different positions to regulate the mixture supply to the engine, a third control switch in the circuit between the magnetic switch and said current source, means operable by engine suction for opening the third control switch when the engine becomes self operative to effect opening of the magnetic switch to cause the starting motor to become inoperative, a generator and means whereby the generator prevents the closing of the magnetic switch as long as the engine operates under its own power irrespective of the condition of said second and third control switches.

18. Starting apparatus for internal combustion engines comprising, a current source, a starting motor operable by current from said source and in circuit therewith, an electromagnet for establishing driving connection between said starting motor and the engine and provided with a winding in circuit with the current source, a single magnetic switch for controlling the circuits between'the current source and starting motor and between the current source and said magnet, a second control switch in the circuit between the magnetic switch and said current source and effective when closed to cause the closing of said magnetic switch, means for variably controlling the quantity of mixture supplied to the engine and operable to hold said second switch closed as the mixture controlling means is moved to different positions to regulate the mixture supply to the engine, a third control switch in the circuit between the magnetic switch and said current source, means operable by engine suction for opening the third control switch when the engine becomes self operative to efiect opening of the magnetic switch to cause thestarting motor to become inoperative, a generator in circuit with the winding of said magnetic switch and operative to set up a counter voltage in said winding when the engine is self operative to cause said magnetic switch to be maintained open whenever the engine is operating under its own power irrespective of the condition of said second and third control switches.

JOHN B. DYER. 

